Materials and methods 1. Materials and equipment

2. Materials and methods 2.1. Materials and equipment The materials used were Tookad ® , acetone 100 , methanol 100 , lactic acid, sulphuric acid, and distilled water. Tookad ® was obtained from the Laboratory of the Ludwig-Maximillian University Pigments, Munich, Germany; while acetone, methanol, lactic acid, and sulphuric acid were obtained from Merck ® . The tool used was a double beam spectrophotometer Varian Cary 50 UV-Vis embedded with volpi lights Intralux 1200. 2.2. Sample preparation Tookad ® was dissolved in acetone and methanol, then homogenized for r 1 min by adding nitrogen gas. The addition of nitrogen gas was intended to avoid contact between Tookad ® and oxygen. Furthermore, the Qy absorbance maximum setting was | 1 at a wavelength λ 300 nm to 1 100 nm. Then, the sample was ready to be used for testing aggregation, acidification, and irradiation of Tookad ® molecules. 2.3. Tookad ® agregation Tookad ® aggregation was tested by titration of distilled water into the sample which had been prepared with a ratio of acetonemethanol: distilled water: 3.0 : 0.0; 2.0 : 1.0; 1.0 : 2.0; and 0.0 : 3.0. 2.4. Aggregates-acidification of Tookad ® After the Tookad ® aggregation conducted, testing aggregates-acidification of the Tookad® molecules done at each concentration series by adding sulphuric acid and lactic acid separately. The entire sample was measured by using a dual beam spectrophotometer Varian Cary 50 UV-Vis at λ 300 nm to 1 100 nm. 2.5. Tookad ® degradation through irradiation Testing of the molecular degradation of Tookad ® by irradiation was performed after Tookad ® had been dissolved in acetone and methanol, aggregated with distilled water, and aggregated and added with lactic acid or sulphuric acid concentration in each series. Irradiation was done by using a polychromatic light with intensity 870 lux lux = 1 lm · m 2 at room temperature 12 . During irradiation, cuvette was closed and stirred. 2.6. Data analysis Analysis of the data includes profile changes of the spectral pattern, difference spectra, and profile changes of the absorbance value toward time interval due to irradiation. Difference spectra is a profile showing the changing patterns of the spectra after treatment of early spectra. The data were processed using the Origin 6.1. Program and interpreted descriptively. 3. Results and discussion 3.1. Tookad